A New Probe of the Molecular Gas in Galaxies: Application to M101

Recent studies of nearby spiral galaxies suggest that photodissociation regions (PDRs) are capable of producing much of the observed HI in galaxy disks. In that case, measurements of the HI column density and the far-ultraviolet (FUV) photon flux provide a new probe of the volume density of the local underlying H_2. We develop the method and apply it to the giant Scd spiral M101 (NGC 5457). We find that, after correction for the best-estimate gradient of metallicity in the ISM of M101 and for the extinction of the ultraviolet emission, molecular gas with a narrow range of density from 30-1000 cm^-3 is found near star- forming regions at all radii in the disk of M101 out to a distance of 12' (approximately 26 kpc), close to the photometric limit of R_25 = 13.5'. In this picture, the ISM is virtually all molecular in the inner parts of M101. The strong decrease of the HI column density in the inner disk of the galaxy at R_G < 10 kpc is a consequence of a strong increase in the dust-to-gas ratio there, resulting in an increase of the H_2 formation rate on grains and a corresponding disappearance of hydrogen in its atomic form.Comment: accepted for publication in The Astrophysical Journal (1 August 2000); 29 pages including 20 figures (7 gif); AAS LaTex; contact authors for full resolution versions of gif figure

Discovery in IC10 of the farthest known symbiotic star

We report the discovery of the first known symbiotic star in IC10, a starburst galaxy belonging to the Local Group, at a distance of ~750kpc. The symbiotic star was identified during a survey of emission-line objects. It shines at V = 24.62+-0.04, V - R_C = 2.77+-0.05 and R_C - I_C = 2.39+-0.02 and suffers from E(B-V) = 0.85+-0.05 reddening. The spectrum of the cool component well matches that of solar neighborhood M8III giants. The observed emission lines belong to Balmer series, [SII], [NII] and [OIII]. They suggest a low electronic density, negligible optical depth effects and 35,000K < T_eff < 90,000K for the ionizing source. The spectrum of the new symbiotic star in IC10 is an almost perfect copy of that of Hen 2-147, a well known Galactic symbiotic star and Mira.Comment: 5 pages including 3 figures. MNRAS Letters accepted. Also available at http://pessoais.ov.ufrj.br/denise

Thiamin and Riboflavin in Human Milk: Effects of Lipid-Based Nutrient Supplementation and Stage of Lactation on Vitamer Secretion and Contributions to Total Vitamin Content

While thiamin and riboflavin in breast milk have been analyzed for over 50 years, less attention has been given to the different forms of each vitamin. Thiamin-monophosphate (TMP) and free thiamin contribute to total thiamin content; flavin adenine-dinucleotide (FAD) and free riboflavin are the main contributors to total riboflavin. We analyzed milk collected at 2 (n = 258) or 6 (n = 104), and 24 weeks (n = 362) from HIV-infected Malawian mothers within the Breastfeeding, Antiretrovirals and Nutrition (BAN) study, randomly assigned at delivery to lipid-based nutrient supplements (LNS) or a control group, to investigate each vitamer’s contribution to total milk vitamin content and the effects of supplementation on the different thiamin and riboflavin vitamers at early and later stages of lactation, and obtain insight into the transport and distribution of these vitamers in human milk. Thiamin vitamers were derivatized into thiochrome-esters and analyzed by high-performance liquid-chromatography-fluorescence-detection (HPLC-FLD). Riboflavin and FAD were analyzed by ultra-performance liquid-chromatography-tandem-mass-spectrometry (ULPC-MS/MS). Thiamin-pyrophosphate (TPP), identified here for the first time in breast milk, contributed 1.9–4.5% to total thiamin. Free thiamin increased significantly from 2/6 to 24 weeks regardless of treatment indicating an active transport of this vitamer in milk. LNS significantly increased TMP and free thiamin only at 2 weeks compared to the control: median 170 versus 151μg/L (TMP), 13.3 versus 10.5μg/L (free thiamin, p<0.05 for both, suggesting an up-regulated active mechanism for TMP and free thiamin accumulation at early stages of lactation. Free riboflavin was consistently and significantly increased with LNS (range: 14.8–19.6μg/L (LNS) versus 5.0–7.4μg/L (control), p<0.001), shifting FAD:riboflavin relative amounts from 92–94:6–8% to 85:15%, indicating a preferred secretion of the free form into breast milk. The continuous presence of FAD in breast milk suggests an active transport and secretion system for this vitamer or possibly formation of this co-enymatic form in the mammary gland

Methane emissions from oil and gas platforms in the North Sea

Since 1850 the concentration of atmospheric methane (CH4), a potent greenhouse gas, has more than doubled. Recent studies suggest that emission inventories may be missing sources and underestimating emissions. To investigate whether offshore oil and gas platforms leak CH4 during normal operation, we measured CH4 mole fractions around eight oil and gas production platforms in the North Sea which were neither flaring gas nor offloading oil. We use the measurements from summer 2017, along with meteorological data, in a Gaussian plume model to estimate CH4 emissions from each platform. We find CH4 mole fractions of between 11 and 370 ppb above background concentrations downwind of the platforms measured, corresponding to a median CH4 emission of 6.8 g CH4 s−1 for each platform, with a range of 2.9 to 22.3 g CH4 s−1. When matched to production records, during our measurements individual platforms lost between 0.04 % and 1.4 % of gas produced with a median loss of 0.23 %. When the measured platforms are considered collectively (i.e. the sum of platforms' emission fluxes weighted by the sum of the platforms' production), we estimate the CH4 loss to be 0.19 % of gas production. These estimates are substantially higher than the emissions most recently reported to the National Atmospheric Emission Inventory (NAEI) for total CH4 loss from United Kingdom platforms in the North Sea. The NAEI reports CH4 losses from the offshore oil and gas platforms we measured to be 0.13 % of gas production, with most of their emissions coming from gas flaring and offshore oil loading, neither of which was taking place at the time of our measurements. All oil and gas platforms we observed were found to leak CH4 during normal operation, and much of this leakage has not been included in UK emission inventories. Further research is required to accurately determine total CH4 leakage from all offshore oil and gas operations and to properly include the leakage in national and international emission inventories

Only connect: unifying the social in social work and social media

This paper utilises ‘Only Connect’, the epigraph from Forster’s novel ‘Howards End’ as the starting point for exploring the challenges and opportunities of integrating social networking with relationship based social work practice. The paper discusses the more deleterious implications of social networking, whilst assuming a deliberately optimistic stance to uncover ways in which the opportunities afforded by online space can be utilised effectively within social work education and practice. Whilst recognising that social networking platforms are transforming constantly, the paper adopts Kaplan’s definition of social media as a ‘group of internet based applications that build on the ideological and technological foundations of Web 2.0’. Whilst much of the discussion within the paper relates to Twitter and Facebook, two of the most endemic international social networking platforms, it is also applicable to myriad forms of social networking. The paper begins with a discussion of UK professional conduct cases and explores these both within Klein’s concept of splitting and historical attitudes to new technologies. Drawing from emerging research data and other examples, the positive relational practices educed by social media within social work education and practice are emphasised and discussed. The paper concludes by highlighting Forster’s plea for connection and recommending that social work embraces the renewed opportunities provided by online networking

The Lantern Vol. 52, No. 2, Spring 1986

• The Cartoonist • Balance • Haiku • Moment of Truth • There Was a Man • Mad Song / Cassandra\u27s Song • Part I - The Descent • Political Thought • Beast • Questions Yet Unanswered • Aphrodite: A Lover\u27s Lament • The Most Limber Boy • Style And • Thoughts From My Confusion • Andy • Momma Wake Up • In The Suburbs • Tommy • When the Phone Rings • There\u27s Something Soothing • Starting Over • A Day in the Life of a Flower • Pretension • It Seems Like So Long Ago • I Walk Along • Insignificant Man • Variations on a Latin Theme • The Riddle • Roll the Dice - Its Your Turn • This Is Your Day • One Night Stand • Make My Day • You Really Can\u27t Expect • Medusa • Don\u27t Think • Broken Chain • Life...A Hammock? • To My Friend • Ode On a Grecian Keghttps://digitalcommons.ursinus.edu/lantern/1128/thumbnail.jp

Antiretroviral therapy provided to HIV-infected Malawian women in a randomized trial diminishes the positive effects of lipid-based nutrient supplements on breast-milk B vitamins

Background: Little information is available on B vitamin concentrations in human milk or on how they are affected by maternal B vitamin deficiencies, antiretroviral therapy, or maternal supplementation

Safety and Reactogenicity of an MSP-1 Malaria Vaccine Candidate: A Randomized Phase Ib Dose-Escalation Trial in Kenyan Children

OBJECTIVE: Our aim was to evaluate the safety, reactogenicity, and immunogenicity of an investigational malaria vaccine. DESIGN: This was an age-stratified phase Ib, double-blind, randomized, controlled, dose-escalation trial. Children were recruited into one of three cohorts (dosage groups) and randomized in 2:1 fashion to receive either the test product or a comparator. SETTING: The study was conducted in a rural population in Kombewa Division, western Kenya. PARTICIPANTS: Subjects were 135 children, aged 12–47 mo. INTERVENTIONS: Subjects received 10, 25, or 50 μg of falciparum malaria protein 1 (FMP1) formulated in 100, 250, and 500 μL, respectively, of AS02A, or they received a comparator (Imovax® rabies vaccine). OUTCOME MEASURES: We performed safety and reactogenicity parameters and assessment of adverse events during solicited (7 d) and unsolicited (30 d) periods after each vaccination. Serious adverse events were monitored for 6 mo after the last vaccination. RESULTS: Both vaccines were safe and well tolerated. FMP1/AS02A recipients experienced significantly more pain and injection-site swelling with a dose-effect relationship. Systemic reactogenicity was low at all dose levels. Hemoglobin levels remained stable and similar across arms. Baseline geometric mean titers were comparable in all groups. Anti-FMP1 antibody titers increased in a dose-dependent manner in subjects receiving FMP1/AS02A; no increase in anti-FMP1 titers occurred in subjects who received the comparator. By study end, subjects who received either 25 or 50 μg of FMP1 had similar antibody levels, which remained significantly higher than that of those who received the comparator or 10 μg of FMP1. A longitudinal mixed effects model showed a statistically significant effect of dosage level on immune response (F(3,1047) = 10.78, or F(3, 995) = 11.22, p < 0.001); however, the comparison of 25 μg and 50 μg recipients indicated no significant difference (F(1,1047) = 0.05; p = 0.82). CONCLUSIONS: The FMP1/AS02A vaccine was safe and immunogenic in malaria-exposed 12- to 47-mo-old children and the magnitude of immune response of the 25 and 50 μg doses was superior to that of the 10 μg dose